<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
     a{
         /* 
         text-decoration:none/line-through(中)/underline/overline(上);
         */
         text-decoration: line-through;
     }
     </style>
</head>
<body>
    <a href="#">hello world</a>
</body>
</html>